September Morn Update

Task/CRC-32/Haskell/crc-32-1.hs

@@ -1,21 +1,26 @@
-import Data.Bits
-import Data.Word
-import Numeric
+import Data.Bits ((.&.), complement, shiftR, xor)
+import Data.Word (Word32)
+import Numeric (showHex)
 
 crcTable :: Word32 -> Word32
-crcTable i = table !! (fromIntegral i)
-        where
-                table = map (\a -> iterate xf a !! 8) [0..255]
-                xf r = let d = shiftR r 1 in
-                        if r .&. 1 == 1 then xor d 0xedb88320 else d
+crcTable = (table !!) . fromIntegral
+  where
+    table = ((!! 8) . iterate xf) <$> [0 .. 255]
+    shifted x = shiftR x 1
+    xf r
+      | r .&. 1 == 1 = xor (shifted r) 0xedb88320
+      | otherwise = shifted r
 
 charToWord :: Char -> Word32
-charToWord c = (fromIntegral . fromEnum) c
+charToWord = fromIntegral . fromEnum
 
 calcCrc :: String -> Word32
-calcCrc text = complement ( foldl cf (complement 0) text )
-        where cf crc x = xor (shiftR crc 8) (crcTable $ xor (crc .&. 0xff) (charToWord x) )
+calcCrc = complement . foldl cf (complement 0)
+  where
+    cf crc x = xor (shiftR crc 8) (crcTable $ xor (crc .&. 0xff) (charToWord x))
 
-crc32 text = showHex ( calcCrc text ) ""
+crc32 :: String -> String
+crc32 = flip showHex [] . calcCrc
 
+main :: IO ()
 main = putStrLn $ crc32 "The quick brown fox jumps over the lazy dog"

Task/CRC-32/Haskell/crc-32-2.hs

@@ -2,12 +2,12 @@ import Data.List (genericLength)
 import Numeric (showHex)
 import Foreign.C
 
-foreign import ccall "zlib.h crc32" zlib_crc32 :: CULong -> CString -> CUInt -> CULong
+foreign import ccall "zlib.h crc32" zlib_crc32 ::
+               CULong -> CString -> CUInt -> CULong
 
+main :: IO ()
 main = do
-        let s = "The quick brown fox jumps over the lazy dog"
-        ptr <- newCString s
-
-        let r = zlib_crc32 0 ptr (genericLength s)
-
-        putStrLn $ showHex r ""
+  let s = "The quick brown fox jumps over the lazy dog"
+  ptr <- newCString s
+  let r = zlib_crc32 0 ptr (genericLength s)
+  putStrLn $ showHex r ""